Thread: Need help figuring this out its driving me Nutz!

package program2;
 
import javax.swing.JFrame;
import java.awt.*;
import javax.swing.JOptionPane;
 
public class Program2 extends JFrame {
 
    private static final int FRAME_SIZE = 500;
    private static final int MAX_NUM = 40;
    private static final int MIN_NUM = 10;
    private static int lineNumber;
 
public static void main(String[] args) {
 
    Program2 guiWindow = new Program2 ();
    //Set Frame Size
    guiWindow.setSize(FRAME_SIZE, FRAME_SIZE);
    guiWindow.setDefaultCloseOperation(EXIT_ON_CLOSE);
    String valueString;
 
    //Create input error trap to ask for Number of lines in the Grid
    do{
        valueString = JOptionPane.showInputDialog("Enter the Number of Lines in the Grid (10-40)");
        guiWindow.lineNumber = Integer.parseInt(valueString);
    } while(lineNumber < MIN_NUM || lineNumber > MAX_NUM);
 
    //Sets window to Visible
    guiWindow.setVisible(true);
 
    }
 
    @Override
    public void paint(Graphics g) {
    super.paint(g);
    Graphics canvas = getContentPane().getGraphics();
    //Gather width,height information
    int width = this.getContentPane().getWidth();
    int height = this.getContentPane().getHeight();
    //Declare my Variables
    double leftGrid = width * .1;
    int leftOfGrid = (int)leftGrid;
    double rightGrid = width * .9;
    int rightOfGrid = (int) rightGrid;
    double topGrid = height * .1;
    int topOfGrid = (int)topGrid;
    double bottomGrid = height * .9;
    int bottomOfGrid = (int) bottomGrid;
    int numberOfGaps = lineNumber - 1;
    double sVertical = (height * .8) / numberOfGaps;
    int spaceVertical = (int) sVertical;
    double sHorizontal = (width * .8) / numberOfGaps;
    int spaceHorizontal = (int) sHorizontal;
 
    //Draw the Horizontal Lines
     int topY = topOfGrid;
    for(int count = 1; count <= lineNumber; count++){
        canvas.drawLine(leftOfGrid, topY, rightOfGrid, topY);
        topY = topY + spaceVertical;
 
    }
 
    //Draw the Vertical Lines
     int leftX = leftOfGrid;
     for(int count = 1; count <= lineNumber; count++){
         canvas.drawLine(leftX, bottomOfGrid, leftX, topOfGrid);
         leftX = leftX + spaceHorizontal;
     }
 
 
    }
 
 
 
 
}

The program compiles fine, I have gotten this far. It's just the fact that the lines on my grid run past where they should.